14 



NOTES AND QUERIES. 



[No. 244. 



some of our princes had been less domineering. 

 In France the ancient form seems to have been 

 retained at least down to the reign of Louis XV. 

 On the occasion of his coronation, it appears that 

 after he had promised to the archbishop to de- 

 fend the rights of the Holy Church : 

 " The people were asked ' whether they accept Louis 

 ... for their king?' And after their consent is 

 given in a respectful silence, the archbishop tenders 

 the king the oath of the realm, which he takes aloud 

 sitting with his head covered, and laying his hands 

 upon the Gospel ; and after this oath is pronounced, 

 the king kisses the Gospels." — Menin's Description of 

 ■the Coronation, p. 138. 



Whatever be the form of succeeding to a throne, 

 the succession must (in the absence of an oracle 

 upon earth) be hy the consent of the people ; and I 

 believe that this consent is asked in every coro- 

 nation ritual except our own. 



Considering the fate of the Stuarts, we may 

 reflect that the English are not a demonstrative 

 people, and often keep their deepest thoughts un- 

 expressed. H. P. 



Lincoln's Inn. 



PHOTOGEAPHIC COERESPONDENCB. 



Mr. Long on an easy Cdlotype Process. — In compliance 

 with your request to be furnished with the particulars 

 of my manipulation in the calotype process, I beg to 

 offer the following as possessing many advantages over 

 the plans as usually recommended. Before doing so, 

 liowever, I would premise what are the conditions 

 necessary for obtaining an impression on calotype paper 

 by the agency of solar radiations. The surface on 

 which we receive the impression is iodide of silver, 

 and to render this coating sensitive to light forms the 

 basis of the various manipulations. If we precipitate 

 iodide of silver from a solution of the nitrate with an 

 excess of iodide of potassium, and spread the resulting 

 powder on paper, it will be found that on exposure to 

 light no effect will be produced ; but if, on the con- 

 trary, the iodide of silver be thrown down from a 

 solution containing an excess of nitrate of silver, a dif- 

 ferent coloured paper will be the result, and on repeat- 

 ing the experiment of exposure to light, a very decided 

 action will be observable on the precipitated mass. It 

 first becomes light brown, and then gradually deepen- 

 ing in colour, it assumes a dark tinge, verging on 

 black. 



We have here evidently two distinct compounds, 

 one sensitive to light, and the other perfectly insensible 

 to that influence. Our object, therefore, in the pre- 

 paration of the paper, is to coat its surface with the 

 sensitive compound, namely, a " sub-iodide of silver," 

 and this I accomplish in the manner following : — 



Pin the paper by two of its corners to a soft wood 

 board, and by means of a glass rod spread evenly on its 

 surface a solution of iodide of potassium of the strength 

 of 20grs. of the salt to 1 oz. of water; allow this to 

 remain for the space of two minvites, and then blot off 



carefully in order to remove the superfluous solution. 

 When the paper is surface dry, repeat the operation 

 with the aceto-nitrate of silver, composed as follows : — 

 Nitrate of silver, pure, 30 grs. ; glacial acetic acid, 

 2 drachms ; water, 1 oz. Let this rest for two minutes, 

 and very carefully blot off as before. If not required 

 for immediate use, the paper thus prepared may be 

 suspended to dry, or it may be immediately placed in 

 the dark slide to await the exposure in the camera. 



The time of exposure will vary from two minutes to 

 fifteen, according to the amount of light, size and focus 

 of lens, diameter of diaphragm, and the nature of the 

 object operated upon. 



On removal from the camera, the paper is to be 

 transferred again to the board, and its surface treated 

 through the agency of the glass rod with a saturated 

 solution of gallic acid, taking care that no part is for a 

 moment allowed to become dry. The picture will 

 now commence to unfold itself in all its details, and 

 will be of a light brown colour. When the whole of 

 the picture is thus far developed, a few drops of the 

 aceto-nitrate are to be spread as quickly as possible 

 over it, in order to change the colour from brown to 

 black, and to give intensity to the dark parts of the 

 impression. 



Care must be taken not to carry the development 

 too far, otherwise the lights of the picture will suffer, 

 and will have a tendency to become brown, greatly 

 impairing the distinctness of the resulting proof. 



The fixing of the negative produced as above is 

 performed by immersion in a bath of hyposulphite of 

 soda, of the strength of 4 oz. of the crystals to one pint 

 of water, where it is allowed to remain until the whole 

 of the yellow colour is dispelled from the light parts. 

 It is then to be removed to abundance of water, and 

 soaked for two hours at least, in order to remove the 

 adhering hyposulphite. After carefully drying, the 

 negative may be waxed in the ordinary way, and will 

 be found in every way equal to those obtained by a 

 more circuitous mode of operation. 



It will no doubt be noticed that the proportion of 

 acetic acid is very high in the aceto-nitrate, but the 

 rationale of its action will be best made clear by de- 

 tailing the following simple experiments: — Precipitate, 

 as before directed, some sub-iodide of silver in two test 

 tubes ; let one of the tubes be now exposed to the action 

 of light, and the other carefully excluded from its 

 influence ; add to each of them a saturated solution of 

 gallic acid; it will be found that both precipitates will 

 become darkened, that which has undergone exposure 

 attaining the darkest hue, the difference being apparently 

 only one of intensity ; such, however, is not the case, as 

 will be seen by adding to each a few drops of glacial 

 acetic acid : in the one that has been exposed, no change 

 will take place ; while, in the other, the whole of the 

 darkness will^disappear, and leave the precipitate of as 

 pure a colour as before the treatment with gallic acid. 



We therefore infer that the object of the large dose 

 of acetic acid in the sensitive solution is beneficial in 

 preserving the light parts of the picture, that is to say, 

 to take up the oxide of silver as soon as it is precipitated 

 by the action of the gallic acid on the light unexposed 

 parts of the negative. 



I must apologise for thus trespassing on your valu- 



